Cimetidine (Tagamet HB) is a histamine H2 receptor antagonist (H2RA) that lowers how much acid is made in the stomach. The over-the-counter (OTC) version relieves and prevents heartburn in people 12 years and older. Higher strengths of cimetidine are prescription only and are used to treat acid reflux, stomach and gut ulcers, and other stomach acid problems in people 16 years and older. Cimetidine (Tagamet HB) is taken by mouth one to four times a day, depending on what stomach problem you have. This medication has few side effects, which can include headache, dizziness, and diarrhea.
Cimetidine (Tagamet HB) is a histamine H2 receptor antagonist (H2RA). It blocks your stomach from making acid. This lowers how much acid your stomach makes, which prevents heartburn and helps heal ulcers.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Rare
Abdominal pain
back, leg, or stomach pain
bleeding or crusting sores on lips
blistering, burning, redness, scaling, or tenderness of skin
blisters on palms of hands and soles of feet
changes in vision or blurred vision
confusion
coughing or difficulty in swallowing
dark-colored urine
dizziness
fainting
fast, pounding, or irregular heartbeat
fever and/or chills
flu-like symptoms
general feeling of discomfort or illness
inflammation of blood vessels
joint pain
light-colored stools
mood or mental changes, including anxiety, agitation, confusion, hallucinations (seeing, hearing, or feeling things that are not there), mental depression, nervousness, or severe mental illness
muscle cramps or aches
nausea, vomiting, or loss of appetite
peeling or sloughing of skin
red or irritated eyes
shortness of breath
skin rash or itching
slow heartbeat
sores, ulcers, or white spots on lips, in mouth, or on genitals
sudden difficult breathing
swelling of face, lips, mouth, tongue, or eyelids
swelling of hands or feet
swollen or painful glands
tightness in chest
troubled breathing
unusual bleeding or bruising
unusual tiredness or weakness
unusually slow or irregular breathing
yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common or rare
decrease in sexual desire
decreased sexual ability (especially in patients with Zollinger-Ellison disease who have received high doses of cimetidine for at least 1 year)
difficult urination
dizziness
drowsiness
dryness of mouth or skin
headache
increased or decreased urination
increased sweating
loss of hair
ringing or buzzing in ears
swelling of breasts or breast soreness in females and males
trouble in sleeping
Not all of the side effects listed above have been reported for each of these medicines, but they have been reported for at least one of them. All of the H2-blockers are similar, so any of the above side effects may occur with any of these medicines.
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Tips for over-the-counter cimetidine (Tagamet HB):
Tips for prescription cimetidine:
No, cimetidine (Tagamet HB) hasn't been banned. In fact, this medication is available over the counter and by prescription. The FDA decided to remove ranitidine (Zantac), a similar heartburn medication, from the market because they found that some ranitidine products had impurities that could potentially cause cancer. As a caution, the FDA also tested a range of other acid-lowering medications, including cimetidine (Tagamet HB). But to date, the FDA hasn't found any cancer-causing impurities in cimetidine (Tagamet HB) products.
No, cimetidine (Tagamet HB) hasn't been discontinued. This medication is available over the counter as a generic medication and branded product (under the name Tagamet HB). Cimetidine is also available by prescription as a generic medication.
Talk to your provider or pharmacist about whether cimetidine (Tagamet HB) is safe to take with your other medications. Cimetidine (Tagamet HB) lowers the amount of acid in your stomach, which can affect how well some medications get absorbed into your body through your stomach. Cimetidine (Tagamet HB) can also lower your body's ability to break down many other medications, like warfarin (Coumadin) and propranolol. This causes the medications to stay in your body too long, potentially build up to unsafe levels, and raise your risk for side effects from these medications. In general, cimetidine (Tagamet HB) has more drug interactions than other acid-lowering medications, so providers and pharmacists might recommend that you take a different acid-lowering medication to be on the safe side.
Both omeprazole (Prilosec) and cimetidine (Tagamet HB) can help with heartburn and other stomach acid problems. The two medications both cause the stomach to make less acid, but they work a little differently. Cimetidine (Tagamet HB) might start to work faster and carry fewer serious risks than omeprazole (Prilosec). But Cimetidine (Tagamet HB) might not work as well as you continue taking the medication. Speak with your provider about which medication best fits your needs.
Constipation wasn't a side effect that people who took cimetidine (Tagamet HB) reported during clinical trials. Speak with your provider or pharmacist if you have constipation while you're taking cimetidine (Tagamet HB). Your providers can suggest lifestyle changes or OTC stool softeners or laxatives to help relieve your constipation.
High blood pressure wasn't a side effect that people who took cimetidine (Tagamet HB) reported during clinical trials. Let your provider know if your blood pressure readings are higher than usual while you're taking cimetidine (Tagamet HB). They might want to follow up with you to make sure your blood pressure is okay.
Speak with your provider about whether you can take cimetidine (Tagamet HB) while pregnant. There isn't enough information to know whether the medication is safe for you and your unborn baby during pregnancy. Your provider will discuss the risks and benefits of taking cimetidine (Tagamet HB) and will recommend the medication only if the benefits outweigh the risks. Some providers might recommend medications like cimetidine (Tagamet HB) when calcium carbonate antacids (Tums) and lifestyle changes aren't enough to help with heartburn or GERD symptoms during pregnancy.
The CDC states that cimetidine (Tagamet HB) can be used as an alternative treatment for young children with molluscum contagiosum, a viral infection that causes a wart-like rash. Providers might use cimetidine (Tagamet HB) in situations when children are scared of the pain from physical methods for wart removal (e.g., cryotherapy, laser) or when parents want to avoid possible scarring from these methods. Keep in mind that cimetidine (Tagamet HB) isn't FDA approved for molluscum contagiosum, so this is considered an "off-label" use of the medication. Speak with your child's provider about whether this medication is right for your child.
Cimetidine (Tagamet HB) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Sometimes, heartburn, GERD, and other symptoms of upset stomach can be signs of serious stomach problems or stomach cancer. Talk to your provider if your symptoms don't completely go away with cimetidine (Tagamet HB) treatment or if your symptoms come back really fast after stopping the medication. Your provider might have to do some tests on you to check for problems that might be more serious.
Some people taking cimetidine (Tagamet HB) have started to have confusion. Confusion might be more likely to happen in severely ill people, people 50 years or older, and people with kidney or liver problems. This confusion can be mild, and it usually goes away either on its own or a few days after stopping the medication. Talk to your provider if you start to feel confused while you're taking cimetidine (Tagamet HB).
Cimetidine (Tagamet HB) can interact with a lot of medications. It lowers the amount of acid in your stomach. This can affect how well certain medications are absorbed into the body through the stomach. Cimetidine (Tagamet HB) can also lower your body's ability to break down many other medications, such as warfarin (Coumadin), propranolol, and amitriptyline, from your system. This can raise the levels of these medications in the body and put you at risk for side effects. Make sure you talk to your provider or pharmacist about potential interactions before starting cimetidine (Tagamet HB).
Cimetidine (Tagamet HB) is available both over-the-counter (OTC) and by prescription. The OTC strength is 200 mg; the prescription strengths include 200 mg, 300 mg, 400 mg, and 800 mg.
OTC dosing for people 12 years and older:
Prescription dosing for people 16 years and older:
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Cimetidine (Tagamet HB) will not be safe for you to take.